Pressure Wave Systems GmbH

Patent Trials and Appeals Board

Jul 15, 2021

2021000635 (P.T.A.B. Jul. 15, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/601,462 01/21/2015 Jens Hoehne WBF-031 2492
47713 7590 07/15/2021
IMPERIUM PATENT WORKS
P.O. BOX 607
Pleasanton, CA 94566
EXAMINER
HUDDLE, HEATHER J
ART UNIT PAPER NUMBER
3763
MAIL DATE DELIVERY MODE
07/15/2021 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JENS HOEHNE
Appeal 2021-000635
Application 14/601,462
Technology Center 3700
Before BENJAMIN D. M. WOOD, LISA M. GUIJT, and
LEE L. STEPINA, Administrative Patent Judges.
WOOD, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 16–18, 21–29, and 36–43. Claims 1–
15, 19, 20, 30–35 have been canceled. Appeal Br. 1–2, 18. We have
jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

1 “Appellant” refers to the applicant as defined in 37 C.F.R. § 1.42(a).
Appellant identifies the real party in interest as Pressure Wave Systems
GmbH. Appeal Br. 1.
Appeal 2021-000635
Application 14/601,462

2
CLAIMED SUBJECT MATTER
The claims are directed to a compressor for a cooling or refrigeration
device. Spec. ¶ 2. Claim 16, reproduced below, is illustrative of the claimed
subject matter:
16. A device comprising:
a compressor chamber;
a membrane that divides the compressor chamber into a first
volume and a second volume, wherein the first volume contains
a working gas and the second volume contains a working liquid,
wherein the membrane is constructed as a balloon that surrounds
the first volume, wherein the membrane is elastic, gas-tight and
liquid-tight, and wherein the working liquid is a hydraulic oil that
surrounds the outside of the balloon;
a first working gas connection that is coupled to the first
volume; a working liquid connection that is coupled to the
second volume;
a pump device that periodically pumps the working liquid
through the working liquid connection and into the second
volume and as a result periodically compresses the working gas
in the first volume;
a cooling device that receives compressed working gas via
the first working gas connection from the first volume;
a working gas reservoir containing the working gas;
a differential pressure regulator adapted to allow the working
gas to flow from the working gas reservoir into the first volume
via the differential pressure regulator and the first working gas
connection when the working gas in the first volume has a
pressure lower than that of the working gas in the working gas
reservoir; and
an over pressure valve adapted to allow the working gas to
flow from the first volume into the working gas reservoir via the
first working gas connection and then the over pressure valve
when the pressure of the working gas in the first volume becomes
too high so as to risk damaging the device, wherein the working
gas is supplied to the cooling device via the first working gas
connection without passing through either the over pressure
valve or the working gas reservoir.
Appeal 2021-000635
Application 14/601,462

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REFERENCES
Name Reference Date
Berry US 2,772,543 Dec. 4, 1956
Martini US 3,473,475 Oct. 21, 1969
Zahid US 3,494,192 Feb. 10, 1970
Clayton US 2009/0158752 A1 Jun. 25, 2009
REJECTIONS2
Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis
16–18, 23, 24, 26–29,
36–39, 41–43 103 Clayton, Berry
21, 22 103 Clayton, Berry, Martini
25, 40 103 Clayton, Berry, Zahid
OPINION
Claims 16–18, 23, 24, 26–29, 36–39, 41–43—§ 103—Clayton and Berry
Claims 16–18, 23, 24, and 26–29
For independent claim 16, the Examiner finds, inter alia, that
Clayton’s gas buffer volume 20 corresponds to the claimed working gas
reservoir, and Clayton’s outlet valve 24 and inlet valve 22 correspond,
respectively, to the claimed differential pressure regulator and over pressure
valve. Final Act. 5 (citing Clayton, Fig. 1). The Examiner relies on Berry to
teach a compressor having a first volume for a working gas separated by a
membrane from a second volume for a working liquid, wherein the
membrane is flexible and constructed as a balloon that surrounds the first
volume. Id. at 5–6 (citing Berry, 2:45–47, Fig. 1). The Examiner
determines that it would have been obvious to one of ordinary skill in the art
“to utilize the hydraulic compressor of [Berry] with the apparatus of Clayton

2 The Examiner withdrew a rejection of claims 18 and 37 under 35 U.S.C.
§ 112(a). Ans. 3.
Appeal 2021-000635
Application 14/601,462

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in order to provide for high compression value without the utilization of
complex machinery and utilize few moving parts.” Id. at 6.
Appellant disputes that Clayton teaches the claimed differential
pressure regulator and over pressure valve. Appeal Br. 10. Appellant
contends that inlet valve 22 does not open “when a maximum set pressure . .
. is reached at the input side of the valve,” and close again “when the
pressure at the input side falls below the maximum set pressure.” Id. (citing
Clayton ¶ 37). Appellant further contends that outlet valve 24 does not open
and close “based on pressure.” Id. at 11. Instead, according to Appellant:
Clayton's inlet valve 22, buffer 20 and outlet valve 24 are used
to vary the refrigeration power of the compressor 1. In normal
operating mode when compressor 1 is operating at full power,
inlet valve 22 is closed irrespective of the pressure on the input
side of inlet valve 22. (Clayton, ¶[0029]). Then when less
cooling power is necessary (when the MRI is on standby), inlet
valve 22 is opened and outlet valve 24 is closed so that the
buffer pressure equalizes to the output pressure on output line
14. (Clayton, ¶¶[0025], [0030]) Thus, inlet valve 22 has no
over pressure function because inlet valve 22 is kept open
regardless of the output pressure on output line 14.
Id. at 10.
The Examiner responds that the claimed differential pressure regulator
“simply needs to be able to maintain a differential pressure,” which
Clayton’s valve 24 accomplishes. Ans. 8 (citing Clayton ¶¶ 18, 19, 25).
The Examiner further submits that paragraphs 30 and 33 of Clayton “clearly
detail the use of the over pressure valve 22 [as] providing an over pressure
function.” Id. at 9.
The evidence does not support the Examiner’s finding that Clayton
teaches the claimed differential pressure regulator and over pressure valve.
Appeal 2021-000635
Application 14/601,462

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The Examiner does not give sufficient weight to the requirement in claim 16
that the differential pressure regulator be “adapted to allow the working gas
to flow from the working gas reservoir into the first volume . . . when the
working gas in the first volume has a pressure lower than that of the working
gas in the working gas reservoir.” Simply being able to “maintain a
differential pressure” is insufficient; all valves, when closed, are supposed to
maintain a pressure differential from the valve inlet to the valve outlet. The
Examiner has not identified any teaching in Clayton that valve 24 is adapted
to allow working gas to flow from gas buffer volume 20 into low-pressure
input line 12 when the input line pressure is lower than the gas buffer
volume pressure.
Similarly, the Examiner has not given sufficient weight to the
requirement in claim 16 that the over pressure valve be “adapted to allow the
working gas to flow from the first volume into the working gas reservoir . . .
when the pressure of the working gas in the first volume becomes too high.”
Paragraphs 30 and 33 of Clayton, on which the Examiner relies, teach that
outlet valve 24 opens when “a reduction in cooling performance may be
tolerated in order to reduce electrical power consumption,” and not when
working gas pressure exceeds a threshold. Thus, Clayton’s valves 22 and 24
are automatically opened and closed based on the operating status of the
MRI system being cooled by Clayton’s cryogenic refrigerator, and not based
on working gas pressures.
Because we are not persuaded that Clayton teaches the claimed
differential pressure regulator and over pressure valve recited in independent
claim 16, we do not sustain the Examiner’s rejection of claim 16, as well as
Appeal 2021-000635
Application 14/601,462

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its dependent claims 17, 18, 23, 24, and 26–29, as unpatentable over Clayton
and Berry.
Claims 36– 39 and 41–43
Like claim 16, independent claim 36 recites a differential pressure
regulator “adapted to allow the working gas to flow from the working gas
reservoir into the first volume . . . when the working gas in the first volume
has a pressure lower than that of the working gas in the working gas
reservoir,” and an over pressure valve “adapted to allow the working gas to
flow from the first volume into the working gas reservoir . . . when the
pressure of the working gas in the first volume becomes too high.” For the
reasons discussed above, we are not persuaded that Clayton teaches these
limitations. Accordingly, we do not sustain the Examiner’s rejection of
claim 36, and its dependent claims 37–39 and 41–43, as unpatentable over
Clayton and Berry.
Remaining Rejections
The remaining rejections rely on the Examiner’s finding that Clayton
teaches the differential pressure regulator and over pressure valve recited in
claims 16 and 36. Final Act. 13–15. As discussed above, we are not
persuaded that this finding is supported by the evidence, and the additional
references relied upon by the Examiner do not cure this deficiency.
Therefore, we do not sustain the Examiner’s rejection of claims 21 and 22
and unpatentable over Clayton, Berry, and Martini; and claims 25 and 40 as
unpatentable over Clayton, Berry, and Zahid.
CONCLUSION
The Examiner’s rejections are reversed.
Appeal 2021-000635
Application 14/601,462

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DECISION SUMMARY
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
16–18, 23,
24, 26–29,
36–39, 41–
43
103 Clayton, Berry 16–18, 23,
24, 26–29,
36–39, 41–43
21, 22 103 Clayton, Berry,
Martini
21, 22
25, 40 103 Clayton, Berry,
Zahid
25, 40
Overall
Outcome
16–18, 21–
29, 36–43

REVERSED